1. Field of the Invention.
The present invention relates to ink jet printers, and, more particularly, to a manually actuated latch mechanism for releasably securing an ink cartridge within a carriage assembly of an ink jet printer.
2. Description of the Related Art.
Ink jet printing involves the ejection of tiny ink droplets through small nozzles in a controlled manner to create the desired image. Ink is supplied from an ink reservoir to a printhead which includes various passage ways from the reservoir to the nozzle orifice. Energy is applied to the ink from an ink droplet generator near each orifice, which may include the application of electrostatic attraction, the application of oscillating forces from piezo elements, the application of heat from heating elements or the like.
Ink jet printers typically include an ink jet cartridge containing the ink reservoir and a nozzle plate containing the nozzle orifices. It is known to provide the ink cartridge on a carriage assembly. The carriage assembly is moved in transverse directions relative to an advance direction of a print medium being transported through the ink jet printer. As the carriage assembly traverses across the print medium, the ink is jetted at selected locations onto the print medium. In the case of a monochrome printer, a single ink is selectably jetted onto the print medium at pixel locations; and, in the case of a multi-color printer, multiple inks are selectively jetted onto a print medium at pixel locations.
It is necessary that the ink cartridge or cartridges be precisely located in the carriage assembly, and it is known to provide datum surfaces on the cartridge and in the carriage to properly reference the cartridge to an exact location. It is also necessary that the cartridge or cartridges be adequately secured in the carriage so that the rapid back and forth movement of the carriage does not cause a cartridge to become unseated.
Since the ink jet cartridge is a consumable item, having a limited supply of ink therein, it is necessary that the cartridge be replaced from time to time. Such replacement should be an intuitive and simple operation, easily performed by non-technically trained individuals.
Various types of latch mechanisms are known and have been used with varying results. Some mechanisms work well in locking and releasing the cartridge, but the cartridge remains difficult to grasp and remove even after the cartridge has been released.
What is needed in the art is a manually actuated latch mechanism for securing in a releasable manner an ink jet cartridge in a carriage assembly which, by simple operation, both releases the latch and unseats the cartridge.
The present invention provides a manually actuated carrier latch mechanism for an ink jet printer that provides a user friendly interface for installing and removing a printhead from a carrier.
The invention comprises, in one form thereof, a latch mechanism for releasably securing a printhead cartridge in a printer. The latch mechanism comprises a cradle for receiving a printhead, the cradle including datum pads against which the printhead is referenced. A latch cover has a pivotal connection to the cradle. The latch cover includes structure for engaging a printhead in two perpendicular planes. An actuator is provided for engaging the latch cover in a closed position. The actuator is adapted for releasing the latch cover by movement of the actuator and for moving a printhead cartridge installed in the cradle by further movement of the actuator.
In another form thereof, the invention provides a printer with a printhead cartridge having a bottom, a top, first and second laterally spaced sides, an inner end and an outer end. The cartridge includes at least one datum pad on the bottom, at least one datum pad on the inner end and at least one datum pad on one of the sides. A carriage is adapted for receiving the cartridge, and includes carriage datum pads for mating with each of the datum pads on the cartridge. Biasing means in the carriage operates against the other side of the cartridge. A latch cover is releasably secured overlying the cartridge top and the outer end. An actuator engages the latch cover in a closed position. The actuator is adapted for releasing the latch cover by movement of the actuator, and for lifting the printhead cartridge by further movement of the actuator.
The invention provides, in still another form thereof, a method of unseating an ink jet cartridge installed in a carriage assembly of an ink jet printer, having steps of providing the carriage assembly with a cartridge cradle, a latch cover pivotally connected to the cradle and an actuator for engaging the latch cover, the actuator being pivotally connected to the cradle; releasing the latch cover by moving the actuator; and moving the printhead by further movement of the actuator.
An advantage of the present invention is providing a user-friendly interface for installation and removal of a printhead cartridge in an ink jet printer.
Another advantage is providing a locking mechanism that promotes proper seating of a printhead cartridge in a printer carriage.
Yet another advantage is providing a mechanism that unlocks a printhead cartridge from a carrier, unseats the cartridge, and repositions the cartridge for easy removal.